Switched antenna with an ultra wideband feed element

Abstract

An antenna that includes an ultra wideband (UWB) feed element, a parasitic conductive element, and a radio frequency (RF) switch. The UWB feed element is capable of radiating a first frequency band. The parasitic conductive element is connected to an electrical ground and capable of radiating a second frequency band. The parasitic conductive element has no electrical contact with the UWB feed element. The RF switch is connected between the parasitic conductive element and the electrical ground and configured to vary an electrical current path between the parasitic conductive element and the electrical ground. The varying of the electrical current path changes a resonant frequency of the second frequency band of the antenna.

1 . An antenna comprising:
 an ultra wideband (UWB) feed element, the UWB feed element being capable of radiating a first frequency band;   a parasitic conductive element, the parasitic conductive element being connected to an electrical ground and capable of radiating a second frequency band, the parasitic conductive element having no electrical contact with the UWB feed element; and   a radio frequency (RF) switch, the RF switch being connected between the parasitic conductive element and the electrical ground and configured to vary an electrical current path between the parasitic conductive element and the electrical ground, the varying of the electrical current path changing a resonant frequency of the second frequency band of the antenna.   
     
     
         2 . The antenna according to  claim 1 , wherein when the RF switch is in an open position the second frequency band of the antenna covers a first resonant frequency band and when the RF switch is in a closed position the second frequency band of the antenna covers a second resonant frequency band. 
     
     
         3 . The antenna according to  claim 2 , wherein when the RF switch is in an open position the first resonant frequency band of the antenna comprises a 900 MHz band and when the RF switch is in a closed position the second resonant frequency band of the antenna comprises a 850 MHz band. 
     
     
         4 . The antenna according to  claim 1 , wherein the first frequency band radiated by the UWB feed element is minimally affected by the changing of the resonant frequency of the second frequency band of the antenna. 
     
     
         5 . The antenna according to  claim 1 , further comprising a second RF switch wherein when the second RF switch is in a closed position the second frequency band of the antenna covers a third resonant frequency band. 
     
     
         6 . The antenna according to  claim 5 , further comprising at least one third RF switch wherein when the at least one third RF switch is in a closed position the second frequency band of the antenna covers at least one fourth resonant frequency band. 
     
     
         7 . The antenna according to  claim 1 , wherein the first frequency band comprises at least one of a 1800 MHz band and a 1900 MHz band. 
     
     
         8 . The antenna according to  claim 1 , wherein a resonant frequency of the first frequency band and a resonant frequency of the second frequency band are increased by decreasing a size of the antenna. 
     
     
         9 . The antenna according to  claim 1 , wherein a resonant frequency of the first frequency band and a resonant frequency of the second frequency band are decreased by increasing a size of the antenna. 
     
     
         10 . A mobile device comprising:
 an input device;   a processor; and   an antenna, the antenna comprising:
 an ultra wideband (UWB) feed element, the UWB feed element being capable of radiating a first frequency band; 
 a parasitic conductive element, the parasitic conductive element being connected to an electrical ground and capable of radiating a second frequency band, the parasitic conductive element having no electrical contact with the UWB feed element; and 
 a radio frequency (RF) switch, the RF switch being connected between the parasitic conductive element and the electrical ground and configured to vary an electrical current path between the parasitic conductive element and the electrical ground, the varying of the electrical current path changing a resonant frequency of the second frequency band of the antenna, 
   wherein the mobile device is capable of communication with multiple networks that use different frequency bands.   
     
     
         11 . The mobile device according to  claim 10 , wherein the mobile device comprises a mobile phone. 
     
     
         12 . The mobile device according to  claim 11 , wherein the multiple networks comprise cellular networks. 
     
     
         13 . The mobile device according to  claim 10 , wherein when the RF switch is in an open position the second frequency band of the antenna covers a first resonant frequency band and when the RF switch is in a closed position the resonant frequency band of the antenna covers a second resonant frequency band. 
     
     
         14 . The mobile device according to  claim 11 , wherein when the RF switch is in an open position the first resonant frequency band of the antenna comprises a 900 MHz band and when the RF switch is in a closed position the second resonant frequency band of the antenna comprises a 850 MHz band. 
     
     
         15 . The mobile device according to  claim 10 , wherein the first frequency band radiated by the UWB feed element is minimally affected by the changing of the resonant frequency of the second frequency band of the antenna. 
     
     
         16 . The mobile device according to  claim 10 , further comprising a second RF switch wherein when the second RF switch is in a closed position the second frequency band of the antenna covers a third resonant frequency band. 
     
     
         17 . The mobile device according to  claim 16 , further comprising at least one third RF switch wherein when the at least one third RF switch is in a closed position the second frequency band of the antenna covers at least one fourth resonant frequency band. 
     
     
         18 . The mobile device according to  claim 10 , wherein the first frequency band comprises at least one of a 1800 MHz band and a 1900 MHz band. 
     
     
         19 . The mobile device according to  claim 10 , wherein a resonant frequency of the first frequency band and a resonant frequency of the second frequency band may be increased by decreasing a size of the antenna. 
     
     
         20 . The mobile device according to  claim 10 , wherein a resonant frequency of the first frequency band and a resonant frequency of the second frequency band may be decreased by increasing a size of the antenna.